This invention relates to the field of optical signal transmission and reception over optical fibers and, more specifically, to the interconnection of optical fibers within a transceiver module with optical fibers and connectors of an optical fiber cable.
In order to interconnect network optical fibers to opto-electronic devices, such as transmit optical sub-assemblies or receive optical sub-assemblies of a computer or server, a typical technique uses a relatively, long optical fiber or pigtail with an interfacing connector on one end thereof. The optical fiber and connector are typically assembled with the optical fiber routed to an opto-electronic device which either produces or receives an electronically generated and controlled optical signal. The assembled device is installed into a host device, and the interfacing connector then is positioned and fixed to the host device.
This handling and positioning of a relatively long pigtail of optical fiber seriously exposes the optical fiber pigtail to damage and breakage, because the optical fiber is very fragile and cannot be sharply bent. Any rough handling or sharp bending of an optical fiber, during manufacture and assembly will cause cracking or breakage of the optical fiber, thereby rendering the optical sub-assembly useless and necessitating replacement of the optical fiber. Replacement of the optical fiber is not always practical, resulting in the entire opto-electronic subassembly becoming useless.
Because the pigtail may be exposed to outside forces after assembly, the optical fiber continues to be subject to damage and must be shielded and protected as well as being provided with connection techniques that will not damage the optical fiber.
Consequently, it is desirable to prevent such possible damage by making the pigtail as short as possible to prevent excessive stresses on the optical fiber pigtail during assembly and handling.
It is an object of the invention to couple a pair of optical fibers together in a simple, reliable manner.
It is another object of the invention to couple a pair of optical fibers without the use of any special tools.
It is a further object of the invention to eliminate the use of long and easily damaged pigtails of optical fiber of opto-electronic devices and modules.
It is an additional object of the invention to reduce the incidence of breakage of optical fibers, which are attached to opto-electronic devices, during assembly and handling.
It is still another object of the invention to permit minor misalignment of an opto-electronic device of a transceiver module relative to a connector by utilizing a short pigtail of optical fiber, and which is entirely contained within the module and protected from damage.
Other Objects of the Invention will become apparent to one of skill in the art once the invention is fully understood.
In order to accomplish the objects of the invention and overcome the problems and shortcomings of the prior art approaches to fabricating and assembling opto-electronic modules with long optic fiber pigtails, any associated potential for pigtail damage must be considered during the critical periods of assembly and connection, where breakage or damage is most likely. Utilizing an optical fiber coupler to interconnect the optical fibers, an optical signal transmitter/receiver module which houses the opto-electronic devices and supports couplers for the optical fibers does not require long optical fiber pigtails.
This optical fiber coupler utilizes a pair of mating, snap-together, tubular shells or members in order to trap and contain a split tubular sleeve. The split tubular sleeve will admit the ends of optical fibers and ferrules attached to the optical fibers and position the optical fiber ends in an aligned, juxtaposed position, thus permitting maximum light transmission across the gap interface between end faces of the optical fibers.
The coupler structure is provided with exterior annular recesses and flanges which mate with a support cradle having complementary flanges and recesses. The support cradle is disposed in and retained in an extended portion of a transceiver module housing. Once assembled, the aligned notches in a cover of the transceiver module housing wall and one wall of a mating module housing cover form a port. An optical fiber may extend through the resulting port and extend between the opto-electronic devices within the module housing and the coupler in the extended housing. The extended housing forms a channel for each coupler and further guides the external cable connector as the ferrule of an external cable connector is inserted into the split coupling sleeve of the coupler.
The most fragile part of the entire opto-electronic transceiver module is the short pigtail of optical fiber extending through an opening in the wall and into the coupler. The coupler allows fixed mounting and retention of the exterior end of an optical fiber, minimizing the potential for damage to the optical fiber during both assembly of the transceiver module and later use of the module such as during connection or disconnection of external optical fiber ends.
This Summary of the Invention is provided as a brief summary description of the invention and is not intended to be used to limit the scope of the invention in any manner.
A more detailed and complete understanding of the invention may be acquired from the attached drawings and the Detailed Description of the Invention which follow.